Is it possible, even by Newton-Raphson, to derive the naturallogarithm of a number using nothing more than addition, subtraction,division and multiplication? I would be keen to get an algorithm todo this - have been trying to derive one myself but with no success.

Post by Eugene GriesselIs it possible, even by Newton-Raphson, to derive the naturallogarithm of a number using nothing more than addition, subtraction,division and multiplication? I would be keen to get an algorithm todo this - have been trying to derive one myself but with no success.

Never mind - I have finally figured out an algorithm that works!Thanks anyway.

Post by Eugene GriesselIs it possible, even by Newton-Raphson, to derive the naturallogarithm of a number using nothing more than addition, subtraction,division and multiplication? I would be keen to get an algorithm todo this - have been trying to derive one myself but with no success.

Post by Eugene GriesselIs it possible, even by Newton-Raphson, to derive the naturallogarithm of a number using nothing more than addition, subtraction,division and multiplication? I would be keen to get an algorithm todo this - have been trying to derive one myself but with no success.

A common method is to use a power series (e.g. Taylor series).

The Taylor series requires raising numbers to powers IIRC. I havefound an elegantly simple 3 step algorithm that seems to work well -I have tested it extensively and it gives the results I require!Thanks. (Personally I have not worked with logs since the 70's! -computers and calculators seem to have killed the need for mostpeople!)